Improvement in furnaces for steam and other purposes



UNITED STATES PATENT OFFICE.

CORNELIUS H. DE LAMATER, OF NEW YORK, N. Y.

IMPROVEMENT IN FURNACES FOR STEAM AND OTHER PURPOSES.

Specification forming part of Letters Patent No. 90,346, dated May Q5,1869.

To all whom it may concern:

Be it known that I, C. H. DE LAM/ATER, of the city, county, and State ofNew York, have invented certain new and useful Improvements in theConstruction of Furnaces; and I do hereby declare that the following isa full and exact description thereof.

My invention is intended more particularly for the furnaces ofsteam-boilersin manufactories and other places on land, but may apply`to furnaces on Steamers, and to various furnaces other than those ofsteam-boilers. It provides for supplying fresh air in small streamsabove Jhe grate, previously heated to a high temperaure.

Many efforts have been made to effect the complete combustion of thevolatile matter in fuel by supplying air thereto after its liberationfrom the solid particles, but al1 are subject to objection from variouscauses, not the least of which is due to the practical difficulties inthe way of properly heating such air before its introduction and thegreat cooling effect and the liability to fail in inducing combustionwhen such air is introduced cold. I overcome the difficulty by myconstruction, which provides passages through which the air is drawn andheated without materially cooling the boiler, and without exposing anysurfaces liable to injury from overheating, andina manner which iseminently practical and may be perfectly controlled.

I will first describe what I consider the best means of carrying out myinvention, and will afterward designate the points which I believe to benew.

The accompanying drawings form a part of this specification.

Figure lis a longitudinal, and Fig. 2 atransverse, section of asteam-boiler furnace constructed according to my invention.

Similarletters of reference indicatelike parts in both the figures.

A isa tubular boiler. B is the ordinary brickworkin which it is set. Ois the grate on which the coal or other fuel is supported to be burned.

It will be understood that my invention may be used withany ordinaryform of boiler and of grates and other accessories.

Iwilldesignatetheinteriorot'thefurnacebyM.

It will be understood that the heat near the fuel is very intense, andbecomes gradually less as the heated products of combustion traversealong under the boiler and impart their heat thereto. At the rear end ofthe boiler, where the gases rise and enter the tubes to return, they arestill very hot.

D is athin Wall of tire-brick, laid either fiat, as usual, or on edge,and forming a partition or side of the furnace.

N is a thin chamber exterior to the wall D, and lying between it and themain brick-work B. I admit the air to the chamber N at the rear of thecombustion-chamber through the openings n, which are controlled byslides O. The fresh air, entering through the openings n, circulatesthrough the thin space N, in contact with the hot partitionwall D, andmoves along in this space under these conditions, constantly receivingheat from the wali D, until it arrives opposite the grate, when itenters the furnace through the small openings p. Entering under theseconditions in small streams at a very high temperature, Athe currentscause the gases with which they mingle to ignite readily and burn at ahigh temperature,'thus yielding their full heatin g-power. In case fromany cause the com bustible gases are not present, or in case they failto ignite, the streams ot' fresh air thus admitted do not exert an;rappreciable cooling effect on the contents of the furnace. The caloricabsorbed in thus heating the intlowing air is taken from the bricksurfaces under conditions which render its loss iuappreciable. Itsimplysaves the outer brickwork of the furnace from becoming as highlyheated as it otherwise would. No appreciable refrigerating effect isfelt on the contents of the furnace. The furnace is everywhereiuclosedin fire-brick of sufficient thickness to maintain the inner surfacesofthe brick at the ordinary high temperature. The quantity of airallowed to circulate through the furnace in this manner may becontrolled perfect-ly by a slide, or series ot' slides, O. When theseslides are nearly closed the quantity of air admitted will be verysmall. When very wide open the quantity will be increased. A blower orother extraneous means may be used, if desired, to

still further increase the quantity.

Instead of discharging the air into the furnace through apertures p atthe sides ot' the furnace, these latter may be made in the bridge 0rmass ot' masonry which extends across the furnace immediately in therear of the grates. In such case the bridge-wall is of coursemadehollow, and the air being admitted may be discharged into the furnace atthe top or either side of the bridge.

I have designated the spaces beneath the boiler by the two names furnaceand combustionchamber,the two spaces being neatly separated by thebridge-Wall.

I can discharge the air into the combustionchamber from the rear face ofthe bridge, but I esteem it notas good as discharging it directly intothe furnace, because the heat is less intense in the combustion-chamber,andthere is more danger that the gas will not ignite, but the heatimparted by going through the thin y spaces N according to my inventiongreatly facilitates the combustion Wherever the air is discharged.

Wall D, induction-orifices n, and discharging-A oriees p, delivering theair thus heated into the innerchamber, M, above the grate, as herein setforth.

In testimony whereof Ihave hereunto set my name in presence ot' twosubscribing Witnesses. CORNS. H. DE LAMATER. Witnesses A. K. RIDER, JoHN O. STEVENS.

